Forest Insect and Disease Survey; Ontario, 1965 - NFIS

TABLE 16
Summary of Damage by the White-pine Weevil in the Parry Sound District
in 1964 and 1965
Per cent trees
Per cent cumulative
Location Tree infested damage all years
township species 196 196 1'6 1°6
McLean rP 0 0 18 18
McLean jP 3 0 41 41
McAulay jP 2 55 57
McMurrich jP 2 0 41 41
McMurrich scP 8 23
MacKenzie scP 13 37
Armour scP 8 12 41 53
Chaffey wP 22 43
Balsam Bud-mining Sawfly, Pleroneura borealis Felt.
As in alternate years in the past, population levels declined at all sample
points. Counts of infested buds did not exceed four per cent at any location
(Table 17).
Location
to shi
TABLE 17
Summary of Balsam Bud-mining Sawfly Larval Counts
in the Parry Sound District, 1962-1965
Av. height of
sample trees
in feet
No. of new buds
examined
Per cent buds infested
1962 1963 l6 1965
McLean 24 227
1.4 17.0 0.0
Chaffey 35 289 15.9 0.6 7.8 0.3
MacKenzie 30 327 6.9 1.1 8.1 3.3
Ferguson 25 296 10.8 2.9 7.1 0.1
Joly 22 311 7.3 1.6 5.8 0.0
Franklin 45 296 6.1 0.4 13.7 0.8
Laurier 35 301 2L0 3.0 11.3 0.8
Wilson 35 360 15.6 0.0 6.0 1.0
10.8
Larch Sawfly, Pristiphora erichsonii Htg.
Population levels of this sawfly have declined since 1962. However, a medium
infestation has persisted in a small 10 acre stand of larch near Byng Inlet in
Wallbridge Township. Defoliation approximated 20 per cent at this location.
Elsewhere, light infestations were observed on occasional trees at several locations.
Defoliation did not exceed 10 per cent.